| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.apache.samza.storage; |
| |
| import java.util.Map; |
| import org.apache.samza.system.SystemStreamPartition; |
| |
| |
| /** |
| * The helper interface restores task state. |
| */ |
| public interface TaskRestoreManager { |
| |
| /** |
| * Init state resources such as file directories. |
| */ |
| void init(Map<SystemStreamPartition, String> checkpointedChangelogSSPOffsets); |
| |
| /** |
| * Restore state from checkpoints, state snapshots and changelog. |
| * Currently, store restoration happens on a separate thread pool within {@code ContainerStorageManager}. In case of |
| * interrupt/shutdown signals from {@code SamzaContainer}, {@code ContainerStorageManager} may interrupt the restore |
| * thread. |
| * |
| * Note: Typically, interrupt signals don't bubble up as {@link InterruptedException} unless the restore thread is |
| * waiting on IO/network. In case of busy looping, implementors are expected to check the interrupt status of the |
| * thread periodically and shutdown gracefully before throwing {@link InterruptedException} upstream. |
| * {@code SamzaContainer} will not wait for clean up and the interrupt signal is the best effort by the container |
| * to notify that its shutting down. |
| */ |
| void restore() throws InterruptedException; |
| |
| /** |
| * Stop all persistent stores after restoring. |
| */ |
| void stopPersistentStores(); |
| |
| } |